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Oh, noes! I am considering it... LS Swap?

DRTDEVL

Mothfukle
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Yeah, later this week, when I have time, I am going to compression test my TBI 454. I think its done (chasing oil leak that really seems to be drive pressure getting into the crankcase and pushing oil out). I don't have the time or inclination right now to rebuild it, and buying short or long block for this thing is stupid money for zero gain. Then I thought, WTF not just give in and find a 6.0 to swap?

So who here has done it? What is the best route? Find a rusty 2500/3500 express van with the engine and computer for cheap? What would I need to change, electronically, for a 1994 4L80e to talk to the computer on an LS? What surprises will I run into along the way? Is there a recommended swap harness to be as close to plug-and-play as possible?

I mean, 323/373 with the ability to get a lot more with a basic tune and dropping torque management is probably going to be better off than 255/405 from the TBI that can't go anywhere further when towing a couple FJ60/62s, right?

Anyway, what's the skinny? Depending upon the donor's price, what other costs am I facing, and what do they currently run? Say a total if I found a 2002-2004 Savana/Express 2500/3500 6.0 that was rusted out for under $1k.

A good long block TBI 454 will run me about $3600... think I could swap for cheaper while tuning for higher torque than the current 405?
 

TRINDU

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This.

While the 6.0 will have more horsetorques than the gofitty4, its still a high strung engine. I'd have something deeper than 3.73s for towing.

considering the 6.0 came with a 4l80e, I'd look into VB differences. should be plug and play if you get the entire donor.

I would love that, but the donors are more difficult to find and demand a lot more money.

what is an 8.1L demanding?
 

DRTDEVL

Mothfukle
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This.

While the 6.0 will have more horsetorques than the gofitty4, its still a high strung engine. I'd have something deeper than 3.73s for towing.

considering the 6.0 came with a 4l80e, I'd look into VB differences. should be plug and play if you get the entire donor.



what is an 8.1L demanding?

$4500 for a high mileage rust bucket. I do see an 8.1/Allison/t-case complete swap listed for $2700 on FB Marketplace, but its all the way down in Kansas City... and I am sure I would have to rebuild and modify the 263 for the pump rub issue on top of that... and not having my truck able to make that trip without blowing out an insane amount of oil on top of it all.
 

TRINDU

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$4500 for a high mileage rust bucket. I do see an 8.1/Allison/t-case complete swap listed for $2700 on FB Marketplace, but its all the way down in Kansas City... and I am sure I would have to rebuild and modify the 263 for the pump rub issue on top of that... and not having my truck able to make that trip without blowing out an insane amount of oil on top of it all.

good to know. I'll hold onto me 8.1/Allison for safe keeping then.

personally, I'd run a NP241/271 before screwing with the slip yoke GM gayness.
 

YotaAtieToo

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There is always the possibility the 6.0 needs a rebuild soon after you drop it in as well. The only one I ever owned ran and drove great on the test drive, then ended up having a lot of issues in a very short time.

I'd honestly do the new long block and maybe put a 3/4 race cam or whatever gets a bit more power out of the fofiddyfo.
 

88mitsu

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Last years of the old 3500hd and a couple years of the chevy express had the 8.1. I think 2000 and 2001, maybe 2002.

Both of those I've seen cheaper than pickups with the 8.1
 

DRTDEVL

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There is always the possibility the 6.0 needs a rebuild soon after you drop it in as well. The only one I ever owned ran and drove great on the test drive, then ended up having a lot of issues in a very short time.

I'd honestly do the new long block and maybe put a 3/4 race cam or whatever gets a bit more power out of the fofiddyfo.

Its funny you say that. I test drove this truck, and it ran flawlessly... for about a month. The leaks began *after* I changed the oil and went with regular 10w30 high mileage synthetic and a bottle of Lucas. I have since added a bunch of oil that it lost, and even a can of that engine restore snake oil junk, but all that did was allow me to drive it easily without blowing smoke out, I still can't go over 60.

As for more power out of the 454? Its pretty limited, due to the in-tank pump. I could always change out to a 1996 model year Vortec pump to get past that issue, but then the TBI itself becomes the issue, at 645 cfm. Only the most mild cam can be supported, and we're only talking a couple ponies at best.

Of course, I could always build a beast of an older 454 and carb it, but that's going backwards in reliability.
 
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YotaAtieToo

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Its funny you say that. I test drove this truck, and it ran flawlessly... for about a month. The leaks began *after* I changed the oil and went with regular 10w30 high mileage synthetic and a bottle of Lucas. I have since added a bunch of oil that it lost, and even a can of that engine restore snake oil junk, but all that did was allow me to drive it easily without blowing smoke out, I still can't go over 60.

As for more power out of the 454? Its pretty limited, due to the in-tank pump. I could always change out to a 1996 model year Vortec pump to get past that issue, but then the TBI itself becomes the issue, at 645 cfm. Only the most mild cam can be supported, and we're only talking a couple ponies at best.

Of course, I could always build a beast of an older 454 and carb it, but that's going backwards in reliability.

Dual tbis? :flipoff2:​​​​​​

I may have gotten a pos, but I don't buy the 6.0 coolaid. Basically meh power and terrible millage. I know you can tune in more power, but you can't tune in more displacement.
 

ANGRYBLACK

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How about the newer tbi efi systems that support more hp? Holley edelbrock and fi tec all make them. Put a cam in the 454 and swap on some 781 casting heads.
 

Grendel

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8.1L and don't look back.

I love that engine.
 

Grendel

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I guess I should look on CL... Cursory searches were on FB only.

Now, how to get that van back here with a bad tow rig...

I have one here in NH. Also one in Texas.

LS swap harness and an 0411 ECM. Thing of beauty. All the benefits of a Big block and LS.

425hp is easy, 500ft lbs, not hard.
 

DRTDEVL

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Well, the final step in diagnostics is delayed. We had one hell of a storm come through Sunday night, which pushed my plans back this week. I spent most of the week cutting up trees that fell on my property. I was going to be able to run a compression test today, but there was a COVID case at my kid's preschool/daycare, so they shut down for the remainder of the week. This left me to finish up the yard yesterday during his nap, and I have to put brakes on the RV (locked caliper) today, as I work Sat, Sun, and Mon, and have an appointment to check into a manifold leak on it for Tuesday (probably the heat riser setup, and they will punch it out and weld it shut for me, as I don't have the time to do that one before Sturgis.

Maybe I'll get to the compression test on Tuesday.

I am also asking myself if this is the right truck for the swap. It may look good, but its a midwestern truck. The stringers under the bed are rotten, and I need new fuel tank straps. It also has the beginnings of rust showing at the bottoms of the fenders and doors. Not bad yet, but that day is coming soon. I also found a small rust hole under the carpet in the passenger footwell, and the blower motor quit the last time I drove it (was intermittent, then shut off, so could be motor, resistor, or control module).

I might just try to dump it for what I have into it and head south looking for another one instead.
 

Grendel

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Well, the final step in diagnostics is delayed. We had one hell of a storm come through Sunday night, which pushed my plans back this week. I spent most of the week cutting up trees that fell on my property. I was going to be able to run a compression test today, but there was a COVID case at my kid's preschool/daycare, so they shut down for the remainder of the week. This left me to finish up the yard yesterday during his nap, and I have to put brakes on the RV (locked caliper) today, as I work Sat, Sun, and Mon, and have an appointment to check into a manifold leak on it for Tuesday (probably the heat riser setup, and they will punch it out and weld it shut for me, as I don't have the time to do that one before Sturgis.

Maybe I'll get to the compression test on Tuesday.

I am also asking myself if this is the right truck for the swap. It may look good, but its a midwestern truck. The stringers under the bed are rotten, and I need new fuel tank straps. It also has the beginnings of rust showing at the bottoms of the fenders and doors. Not bad yet, but that day is coming soon. I also found a small rust hole under the carpet in the passenger footwell, and the blower motor quit the last time I drove it (was intermittent, then shut off, so could be motor, resistor, or control module).

I might just try to dump it for what I have into it and head south looking for another one instead.

What's the goal?

A beater? A show truck?
 

DRTDEVL

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What's the goal?

A beater? A show truck?

Neither. I want a simplistic, reliable tow rig to keep for many years. I have a son, he'll be getting pretty tall in another decade and beyond, so crew cabs are preferable. I have some property, so long bed is preferable. I tow a lot, so dually is preferable. I live in snow country, so 4wd is mandatory (not just the snow, but even driving off the pavement in the spring will sink a 2wd). I live where -30 isn't uncommon in the winter, so gas is preferable. I am not financing anything, and am currently low on non-emergency fund savings due to the city adding sewer and charging all of us a connection fee ($15k plus contractor costs to stub in), so preferably under $6k.

Note: The only mandatory is 4wd. It can be an ext. cab, it can be SRW, it can be short bed, etc. It just needs a good tow capacity and have a history of reliability. Oh, and no rust buckets (eliminates 99% of the local market).
 

Grendel

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Neither. I want a simplistic, reliable tow rig to keep for many years. I have a son, he'll be getting pretty tall in another decade and beyond, so crew cabs are preferable. I have some property, so long bed is preferable. I tow a lot, so dually is preferable. I live in snow country, so 4wd is mandatory (not just the snow, but even driving off the pavement in the spring will sink a 2wd). I live where -30 isn't uncommon in the winter, so gas is preferable. I am not financing anything, and am currently low on non-emergency fund savings due to the city adding sewer and charging all of us a connection fee ($15k plus contractor costs to stub in), so preferably under $6k.

Note: The only mandatory is 4wd. It can be an ext. cab, it can be SRW, it can be short bed, etc. It just needs a good tow capacity and have a history of reliability. Oh, and no rust buckets (eliminates 99% of the local market).

I used those as examples.

Sounds like you should find a rust free truck from AZ ... with an 8.1L and do a mechanical restoration on it.
 

DRTDEVL

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Its official... Cylinders 3, 5 and 6 are in the 90s, cylinder 7 is down to 40.

Looks like another can of engine restore, clean out all my stuff, and try to get most of what I put in out of it. I'm going to check with my little sister in TN about finding me an 8.1 crew 4x4 with relatively low miles at the auctions. She's the regional manager of a small-time southeastern used car chain and has offered to find me whatever vehicle I want at dealer cost in the past... hopefully that offer still stands.
 

DRTDEVL

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Yup. Deal's still on, but she advised to wait a couple months, because with low new car inventories, used are selling for retail at auctions right now. She has no clue what they are going for, because they mainly look for newer diesels... but her eyes will be out for a mid-2000's Chevy or GMC 3500 Crew 8.1 4x4 with relatively low miles.
 

shortbus4x4

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Yup. Deal's still on, but she advised to wait a couple months, because with low new car inventories, used are selling for retail at auctions right now. She has no clue what they are going for, because they mainly look for newer diesels... but her eyes will be out for a mid-2000's Chevy or GMC 3500 Crew 8.1 4x4 with relatively low miles.

Good call. Once you drive a 8.1 truck you'll never go back to even thinking about a 6.0.
 

4Eyedturd

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I have one here in NH. Also one in Texas.

LS swap harness and an 0411 ECM. Thing of beauty. All the benefits of a Big block and LS.

425hp is easy, 500ft lbs, not hard.

8.1? In Texas you say? Is it for sale?
 

TRINDU

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Yup. Deal's still on, but she advised to wait a couple months, because with low new car inventories, used are selling for retail at auctions right now. She has no clue what they are going for, because they mainly look for newer diesels... but her eyes will be out for a mid-2000's Chevy or GMC 3500 Crew 8.1 4x4 with relatively low miles.

That's not going to happen for $6000.

I've been grabbing vehicles off CL/FB and sending them to auction. Money is easier and quicker, fuck dealing with the public. I dont have a fucking clue what's going on right now, it's stupid.
 
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4Eyedturd

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Thanks assholes, now I’m looking for an 8.1/Allison for my 3/4ton. Like I need more shit to do
 
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